This disclosure relates to test and measurement instruments, in particular to test and measurement instruments and methods of calibrating the same using an internal reference.
Logic Analyzers are test and measurement instruments that include a large number of channels used to test digital data on a device under test. During calibration, manufacturing, or the like, setup times and hold times can be measured for individual channels. In addition, skew between channels can be measured.
To perform such measurements, the channels of the logic analyzer are driven with a calibration signal. However, at least one of the channels, and possible one entire probe attached to the logic analyzer would be driven with a signal used as a reference signal to trigger acquisition. As that channel and/or probe was used for triggering, the performance of that channel could not be simultaneously measured. Once the measurements were performed, the test setup is changed so that input channel used as the reference signal can be driven. However, a different one of the input channels must then be used for the reference signal to measure that channel.